Various facet fixation techniques are known to those of skill in the art. The universal cannulated screw system of Medtronics includes a translaminar cannulated screw that is placed by guide wire across the facet joint from an entry point at the spinous process/laminate junction. This is opposite the actual facet joint, closing through the lamina and facet joint proper. The system provides only for static stabilization using a translaminar, open approach, with significant dissection. The fixation is non-locking.
The Nuvasive facet fixation system is a non-translaminar approach utilizing a single screw through the facet joint and trajectory down into the pedicle. The screw pathway is oblique to the joint surface. Although open or micro techniques may be used, the system is non-locking and limited to static fixation.
The Dynasys system from Zimmer, which is a dynamic pedicle fixation device, utilizes pedicle screws attached to an elastic-type “rod” covered in a silicone spacer. The system is dynamic only and must use an open technique. The facet joint is not involved.